Paper-drying machine



' Mayf15, 1928.

M. J. OMALLEY PAPER DRYING MACHINE Filed A112. 12. 1927 Patented May 15,1928.

MICHAEL J. OMALLEY, OF CHICAGO, ILLINOIS.

PAPER-DRYING- MACHINE.

Application filed August 12, 1927. Serial No. 212,489.

My invention has relation to improvements in paper making machines, andis more particularly directed to that part of the machine wherein thepaper web is dried.

5 It consists in the novel features of construction more fully set forthin the specification and pointed out in the claims.

In paper machines of the Fordrinier type, the drying rolls,

prise heavy iron or steel drums which contain steam under considerablepressure, for the purpose of supplying the heat that dries the paperweb. Of course, the use of steam entails a boiler and the employment ofan engineer at considerable expense. Then, too, the water ofcondensation resulting from the circulation of steam must be taken careof as well as all other difliculties that are encountered when steam iscirculated as 50 a heating medium. a

I propose to overcome such difiiculties as are alluded to in dryingrolls of a paper making machine by utilizing heated air as a heatingmedium instead of steam. Among 2 the advantages gained by the use of airare:

1. A more rapid heating of the drying rolls, enabling the machine to bestarted in operation more quickly.

2. A more simple and considerably 3 cheaper apparatus, since the rollsneed no longer be built to resist steam pressure but may be made ofcomparatively thin sheet copper or other suitable metal; and steam pipefitting is eliminated.

3. A safer apparatus because there is but a negligible pressure in thedrums and no danger of drums blowing up because of excessive steampressure. 7

Further and other advantages will be, better apparent from a detaileddescription of the invention in connection with the accompanyingdrawings, in which- Figure 1 is a top plan of a pluralitypf drying rollsshowing my invention applie thereto; Fig. 2 is a side elevation thereof;'Fig. 3 is an enlarged vertical longitudinal section taken on the line33 of Figure 2; and Fig. 4 is a vertical cross-section taken on the ine4-4 'of Fig- 3.

Referring to the drawings, 1, '1, 1, etc. represent dryin rolls of apaper-making machine, said ro ls being hollow drums preferably made ofcomparatively thin sheet copper, because of its high heat conducutivity, each of said rolls being provided with as is well understood,com- 10 through the trunnions 2,

hollowtrunnions 2, 2 on their end walls, by 1 means of which each rollis rotatably mounted in bearings 3, 3 of supportlng frames 4,4. As iswell understood in the art, the rolls are geared together so that theywill rotate in unison to carry the paper web 5 smoothly and withoutstrain over the entire set of drying rolls, and ultimately to thecalender rolls 6, 6. The gearing has been omitted from the illustrationfor the sake of clarity, since this invention is not concerned withanything other than the means for heating the rolls.

A heating unit comprising, in the present instance, a heater 7, fan 8,and motor 9, is set up in proximity to the drying rolls, and conduits10. and 11 are arranged adjacent to the ends of the rolls. Conduit 10leads from the fan outlet 12 and conduit 11 leads to the inlet 13 oftheheater 7, or vice versa, the outlet 14 of the heater being connected tothe inlet 15 of the fan. 16, 16, etc. lead from the air supply con 2, ofthe respective drumsl, and thence to the return conduit 11. Thus eachdrum has a pipe passing entirely through it, a slight clearance beingprovided' through the trunnions, each of whichhas a suitable packing nut17 and gasket 18 to prevent leakage of the hot air from the drum (Fig.3).

' A partition 19 is fixed in each pipe 16 at the center of that partwithin the drum, said partition dividing the pipe 16 into a supply pipe0. and a return pipe I). A plunality (in the present case three) of discharge heads 20 lead from opposite sides ofthe supply pipe 01, each head20 terminating in an elongated nozzle 21. Both rows of nozzles 21 extendalong the entire length of the drum and in close proximity to the innersurface 8 thereof, so that air issuing from the nozzles will impinge onthe inside d drum surface along two lines op ositely disposed. As thedrums revolve, t e pipes 16 remaining stationary, the hot air issuingfrom the nozzles will, of course, be discharged against the entire innersurface of the drums. While I have shown but two sets of discharge heads20, obviously any desirable number of sets may be used.

Branch pi es uit The heated air that is discharged from the V nozzles 21escapes into the drum 1 from where it is forced, by the oncoming air,through a plurality of perforations o, 0

etc. in the return side I) of the pipe 16/ From the pipe 16 the used airreturns to the heater through conduit 11.

Thus a continuous circulation of hot air passes into and through thedrums.

Having described my invention, I claim:

1. In a. paper drying machine, a drying roll over which the paper isadapted to pass, said roll comprising a hollow drum of sheet metalconstruction, a source of heated air supply, a conduit leading from saidsource of supply into the drum and back to said source, a partition inthe conduit within the drum, nozzles leading from the conduit on oneside of said partition and adapted to discharge air against the insidesurface of the drum, the .conduit having inlet openings on the oppositeside of the partition, and means for circulating the air.

2. In a paper drying machine, a dr ing roll comprising a hollow drumover w iich the paper is adapted to pass, an air heater, an air conduitleadin from the heater into said drum, said conduit having elongateddischarge nozzles in close proximity to the inside cylindrical wall ofthe drum and extending longitudinally thereof adapted to discharge athin sheet of heated air against said wall, an outlet conduit for thespent air, and means for continuously circulating the air.

In testimony whereof I hereunto affix my signature.

MICHAEL J. OMALLEY.

